Underwater lighting poses a number of problems which need not be faced in accomplishing most lighting tasks and that is particularly true when lighting swimming pools and spas. In most underwater lighting projects, and obviously in the case of pools and spas, the light source, the lamps, must be mounted in or behind the containing walls of the pool or spa, and the electrical wiring must be located behind those walls. The result is that there are wall openings. Openings give rise to opportunity for water leakage and consequent corrosion, for leakage and short circuit current flow, and for possible electrical shock to occupants of the pool or spa. The difficulty of creating a design that provides safety for the system and for users is multiplied by the need to provide for replacement of lamps.
The solutions of the past rely on special seals against passage of water to electrical connections and other elements of the electrical system, elaborate drains for discharging any leakage, and metal grounding screens and barriers to keep users from contact with electrical elements in the case of leakage and lamp breakage.
While the expedients of the past are effective to protect both lighting systems and pool and spa users, underwater lighting has generally been used only in public pools and in higher cost private pool construction, and not at all in private spas because of cost and maintenance difficulty.
The electrical codes of most jurisdictions require the inclusion of ground fault sensors in the energizing circuitry of underwater lighting systems. But those devices are easily bypassed. Many codes and insurance underwriters establish maximum current standards which must be met, with and without lamp breakage, when the ground fault sensor is removed or rendered inoperative. Those standards define maximum current levels in the pool and spa water at prescribed distances from electrical system components. The prior art solution has been to install physical barriers to prevent users from getting close to any electrical elements.